DEVELOPMENTAL-CHANGES IN LIPOGENIC ENZYME-ACTIVITIES IN LIVER AND ADIPOSE-TISSUE OF POST-WEANING RATS - EFFECT OF SEX AND CASTRATION

The specific activities of acetyl-Co-A-carboxylase, malic enzyme (decarboxylating) and glucose-6-P dehydrogenase were determined in the liver and adipose tissues of rat. At weaning, Wistar CF rats were divided into 4 groups (males, females, castrated males, castrated females) and fed a low fat diet ad libitum. Eight animals of each group were killed at different ages (25, 36, 42, 50 and 70 days). The results of the study showed that: in both sexes as well as in castrated animals, the adipose tissue was the site of intense lipogenesis between weaning and 50 days, but that its lipogenic capacity declined during adulthood; that, as compared to adipose tissue, the liver might play a considerable role in de novo fatty acid synthesis, i.e. acetyl-CoA-carboxylase activity of the liver represented at least 70% of the whole 'liver+perirenal and subcutaneous adipose tissue' activity; the differences in acetyl-CoA-carboxylase activity caused by aging might account for the variations in adiposity of the 4 groups of animals between weaning and 50 days; and that sex and castration had only a weak effect on the activity pattern of the 3 enzymes studied in the adipose tissue, while the effect of sex and castration was evident in the liver, especially after 50 days.